Railway traffic controlling system



SePt- 18, 1934 G. c. WHITNEY lRAILWAY TRAFFIC CONTROLLING SYSTEM Filed July '7, 1951 Patented Sept. 18, 1934 f RAILWAY TRAFFrccoN'rRoLLING srsTEM r m Gilbert c. Whitney, New. Yoran. Y.. Application July 7, 1931, Serial No. 549,148

13 claims. VA(c1. 246-135) This invention relates to railway traffic controlling systems in general, more particularly vtc the operation of power operated track switches, and specifically to a .novel means providing for .5 release operation of a plurality of such track switches whether operated or controlled electrically Vor electro-pneumatically and to provide a signal in the approach to such' track switches and has for an object to increase the safety of traiic overV such track switches.

The invention herein disclosed'refers to the same subject 'matter as my co-pending applications, Serial Nos. 554,893, filed August 3, 1931, and 558,663, led August 22, 1931, and relates to my prior Patent No. 1,421,880, issued July 4, 1922.

The established practice 'of the art requires that a Ymeans be provided to prevent the' operation ofA a track switch when such operation would be dangerous to a train moving over such switch. This is particularly important where the switch is operated by power. Associated with the track switch there is usually a signal which, when in the clear position, indicates, among other things, that the track 'switch is in a safe-position for the passage of the train. This safety is usually obtained by a system` of mechanical locking between the lever which controls the signal and the lever which controls the switch. Coupled with this there is an electric lock on the signal lever controlled by the presence of a train on the track in the approach to the signal and so arranged that this lever, if the signal was cleared for the train, cannot be placed in a position tov release the lever controlling the switch while the train occupies said track section in the approach to said signal.` Alsof there is an electric'lock on the switch lever, Ycontrolled by the presence of a train on that "portionv oi :track in 'which the track switchis'located. These electric locks may be of the gravity drop type or of the forced dropl type, inr which types the locking elementa plunger, or l' equivalent`,-engages with theV movable lever element to prevent the lever movement under 'certain conditions. This arrangement'is known as approach' locking and detector locking according to its application. In the arrangement, above referred to, `itwill be noted Ythat the object sought is to prevent the operation of a track switch and the means used to-obtain this effect isapplied in an indirect manner, `iirst to the lever controlling the signal and then to the lever controlling the switch. It should also be noted,' that, as a track switch has twopositions so, also, must its .controlling lever have twopositions and in order to have the electric lock effective in both positions an obstruction on the leverelement is necessary so that the locking element may take effect. `Said obstruction introduces a neutral zone in which' said locking element cannot take effect to prevent completing an operating circuit at least once.

My invention, Patent No. 1,421,880 provided a system of protection embodied in theV circuits which control and operate an electrically operated switch mechanism which prevents an operation of the switch with a train on the same portion of track, orxin the approach to said portion of track, without regard to the position of the signal lever and, in addition, if the switch mechanism has startedwhen the train approaches, it will complete fsaid mechanism movement and thereby prevent -derailment, but when such movement is once' completed the switch cannot again be moved Vuntil the track section is unoccupied. Also, said invention provided a release means arranged to require the positive cooperation of the engineman, or motorman, as will be appreciated.VV

My co-pending application Serial No. 554,893 disclosed a novel means of release and included av special signal indication at the location of the release .actuating device.` f

In this application I disclose a novel means of releases and special signal indications at a plurality Aof locationsV and releasably controlling a plurality yof switch operating mechanisms on a sin'gletrack orV on a plurality of tracks to which any signalvmay govern.

Notwithstanding the fact vthat I have illustrated and will describe this present invention in connection with the same certain form of all-electric operated switch operating mechanism system set forthin my prior Patent No. 1,421,880, it will be clearfrom the drawing and specilication ythatzI have invented a release device and signal means system of broad-application equally applicable to the electro-pneumatic type of power operated track switch.- p In order that-my present invention will be understood' more readily I have `herein v repeated the essentialv parts of the specification of my former Patent No.` 1,421,880 and have shown in the accompanying drawing a simplied circuit ,outline illustrating and distinctly portraying this Fig. 2, I have shown a modified detail of the release means and signal indication means. Like characters represent similar parts in each gure and are similar to those represented on the drawing of my co-pending application.

Referring to Fig. 1; in conventional single line form 101 represents both track rails of one track 101 while 102 represents bothrails of the other track 102. ItV willbe understood, of course, that the rails of either track are insulated from each other in order to permit the working of a track circuit. 11 and 111 representing the two track switches dene the limits of thecrossover track. Both tracks are divided into tracksections A, B, and C on one track and AA, BB, and CC on the other track, by insulated track rail'j'oints 103. 11 is a track switch leading from track 101 to track 102 and 111 is a track switch leading from track 102 to track 101. A track circuit is provided for each of the track sections A, B, C, AA, BB, and CC and appropriateparts of the crossover track are included in track circuits B and BB, inthe usual manner, as will be appreciated.v Each track 'circuit includes a source of energy (not shown), the

respective track rails and a track relay appropriately identied as 22, 23, 122, and 123. A signal l6'is located atthe entrance to the block B to protect switch 11 located in this block and a signal 116 is located at the entrance to the block BB to protect switch 111 located in this block. No part of the track circuits for sections C and CC are shown because they are not essential to a complete understanding ofthis invention.

The switch 11 is controlled by lever 11a represented by dotted lines and contacts, located in tower 12, said contacts being represented in conventional simplified form and operative according to the legend of levercontact operation set forth on the drawing. vLever 11a has a normal and rehave a preliminary movement limited by a system of indication locking (not shown but commonly used and well-known in this type of inter-J locking) which prevents the lever from making up theextreme contact N or rR, as the case may be, unless and until the corresponding switch operating mechanism has completed its movement, by bolt-locking the switch, and indicated. It should also be understood that levers 11a and 111a may or may not be operated as one lever or simultaneously, and may be operated in any sequence-'and at any time.

In the interest of simplicity only,I have omitted the showing of the circuits connected to a source of energy and therefore, it -is to be understood that a suitable source of energy (battery) is connected between Wires 50 and 51.

The operation of switch 11 by lever 11a will now be described:-If lever 11a be moved to the reverse operating (indication) position, contact RD will be made and this sets up the conditions for operatingthe switch mechanism, as follows: Current battery (wire 51), wire 52, contact 53 of safety relay 24, wire 54 to holding coil of relay 24. Thence via wires 55 and 56,. lever contact RD, wire 57, contact 34 on switch mechanism, wire 60, motor eld 32 for reverse movement, motor 14,

wire 61 to battery (wire 50) The motor, through connection 31, operates the track switch to its reverse position and on completion of the movement opens contact 34 and closes contact 35. This places the circuits in position to operate the track switch back to the normal position again when lever 11a is moved to the normal operating (indication) position. The operating circuit can be traced as before; from wire 55, lever contact NB (now closed), wire 58, contact 35 on switch operating mechanism (now closed), wire 59, motor field 33 for normal movement, motor 14, and wire 61 to battery (wire 50). This circuit is fundamental to electrically controlled track switches whether operated by direct or alternating current and whether operated by one or moreV sources of power.

' As pointed out in my Patent No. 1,421,880, the novelty in the use of the safety relay 24 resides in its maintaining the operating circuit if the motor14'is drawing current from battery (wires 50-51) and preventing the operating circuit be.- ing established if the motor 14 is not drawing current from said battery (wires 50-51), and either contact '72 of relay 22 or contact '74 of relay 23 is open due to the fact that the pick up coil of this relay 24 is controlled by the track circuits from wires 51 and '71', contact '72 of relay 22, wire 73, contact 74 of relay 23, and wires 75 and 76, to re lay 24, to wire 50. In addition to the track circuit control of the pick up coil of relay 24, above described, I provide a levercontrolled pick up circuit, for the pick up coil of relay 24,v which is effective, whenever lever 11a is in the normal or reverse position, to maintain relay 24 picked up independently of said track circuit control and thereby avoid needless voperation of relay 24. This 'lever controlled pick up circuit may be traced as follows: from battery (wire 51V), wire 80, lever contact N, wire 76, topick up coil of relay 24 and wire 77 to battery (wire 50) when lever 11a is in the normal position. Contact R and wiresr 78 and '79 provide a similar control when lever 11a. is in the reverse position, as will be appreciated.

As above stated, lever 11a has a preliminary movement which prevents lever contacts N and R being made unless certain conditions have been set up, and therefore, while the lever 11a moves between the normal operating (indication) and reverse operating (indication) positions, lever contacts N and R cannot be closed, and thus when lever 11a, is in an operatingposition the circuit of the pick up coil of relay 24 will be open. Thus, when the lever 11a is moved to operate the switch mechanism the pick up coil of relay 24 is controlled over track relays 22- and 23, and this circuit of the pick up coil will, therefore, be open with a train voccupying track sections A or B.

, It has been shown that the operating current for the switch mechanism is takeny in series through the holding coil of safety relay 24 and through contact 53 .when this relay is energized. The following conditions, therefore, result; When the lever 11a is placed in either N or R position, relay 24 is energized by the pickup coil; when the track sections are unoccupied this relay is also energized by the pick up coil; when the switch mechanism is drawing current this relay 24 is maintained energized by the holding coil; when this relay 24 is deenergized the switch cannot be operated by power. Attention is here directed to the fact that contact 53 does not open while the switch mechanism is drawing current,

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and no provision, therefore, is necessaryto 'guard against arcing of the Vcontact even when this circuit is operated von high voltage.. Attention is also directed `to the fact that I may separate the functions of the element (relay 24) into two or more .relays with the same ultimate resultas I have obtained vwith but one. relay. By virtue of contact 53, vrelay24'becomes a stick relay.

The application Aof this system will be understood by considering the approach of a train in the `direction of the arrow on track 101. When the `signal 16 .is clear, the route is established for the through movement of the train and. when the train is on section A or B a'movement of the lever '11a cannot produce a corresponding kmovement of the switch 11 since the pick up coil circuit of relay 24 isopened by the track relays and is also opened by the movement of the Vlever 11a, before the operating circuit is established, hence contact 53 will be open thus preventing current flow to the switch operating motor. Now, if the switch movement is partially made when the train enters section A, although the Vpick up coil of relay 24 will be deenergized, the holding coil of this relay is energized until the operating circuit is opened at contacts 34 or 35 upon completion of the movement, when relay 24 becomes deenergized. Section A is of such length that a train at maximum speed passing over it will consume a greater time interval than that necessary for the cornplete operation of the track switch movement. Where necessary, an additional section of track may be arranged to control the circuit of relay 24 for this purpose. By this arrangement switch 11 will be in position and locked before the train enters upon section B and it cannot again be moved until .the train passes off this section. This system, therefore, becomes a substitute for approach locking, provides track circuit control of the switch mechanism, and insures a completed .movement of the switch independently of the track circuit control, allin the most direct manner and independent of the position or subsequent movement .of the signal or its controlling lever and also independent of. the position of the switch mechanism or thev position or subsequent movement of its controlling lever.

In practice it frequently happens that the route cannot be establishedforan approaching train and the signal remains in the stop position. In dense traic, for instance,y a previous train may not have cleared the routel when the following train enters upon section A; signal 16 is used to stop said following train.l It occasionally happens that a train will over-run the signal, or a train may pass signal 16 in thefstop position on the instruction of `a hand signal or flag. Without the protection afforded by this invention under these conditions theswitch lever is free to be moved and .to operate the switch mechanism until the train enterssection' B when anlelectric detector lock, not shown inl therdrawing but commonly used in practice,1estricts the movement of the lever. Now, if the lever 11a is placed in an operating position just before thetrain enters section B, and if the time consumed by the train in covering thedistance D is less than the time interval Afor the operation ofthe switch mechanism, it is apparent .that the front of the train will pass over the switch rails before their movement is fully completed, thereby leading to a derailment. With the invention of my former Patent No. 1,421,880, this cannotoccur as Vthe track circuit control'of the switch extends over section A as well as section ,y I It will be clearly evident also, that if the train passes over 'the track -c'ircuitsbeginning with sectionCfand ending with section Azor if the train passes from track 102 over switches 111 .and 11 asfar assection A': in other words, if the train runs over the system in the opposite direction and, while it is occupying section A or B the leverA or actuating device should be operated, the switch 11 would not operate because the switch operating circuit would be open at contact 53 on relay 24, but asrsoon as track `circuit Abecame vunoccupied-track circuit B remaining unoccupied-#relay `24 will become energized closingthe switch operating circuit at c'ontactf53` thus operating *switch'll to a. position tocorrespond with its lever Aor' actuating device, thereby effecting, vin a safe manner, an entirely automatic operation `of the track switch.: `By employing any of lthewellknown systems Vof directional released routelocking the above described switch operation may be made Veffective when the train has'cleared track circuit B. i f

In the above description Ik have Vexplained the functioning of the system in the ordinary course of' events as set forth in` my Patent 4No5 1,421,880 and the 'description of this present vinvention will now proceed. i

In the ordinary course of operation, it is, of course, necessary at times to beable to operate the switch 11 when a train is stopped at signal 16 and occupying section'A. I provide for this by requiring the positive cooperationiof the engineman or motorman together with the operation of the lever 11a to sei'l up the conditionsfor operating the switch mechanism.

As shown in Fig. 1, I have provided'a release means including wire 82 extendingfrom wire 54 at relay 24, to anindication means special signal lamp 89, located in the vicinity of signal 16, thence via wires 84 and 71 to battery (wire 51). Also, I provide a circuit including wire 95, connected to battery 'at wire 84, and including normally open manually operableself-restoring contact 98, located at signal 16,"wire .96, relay 62 which may be located'at signal'l or elsewhere, wire 97a connecting to wire 82, and when 'contact 98 'is closed this circuit establishes'a low resistance shunt around lamp 89. I have also'illustrated a checking circuit including wires 100 and 101 and normally closed self-'restoringfcontact 102 manually operable with contact 98 by operating member 94' to insure that Contact v98, after operation, is restored to the `n'ormallyopen position. This checking circuit may be included in'any suitable signal or automatic stop control circuit, as willv be appreciated.

When the train is standing at signal 16, contact 'I2 of track relay22 being open and it is desired'to operate switch l1 tothe reverseI position to route rthe train' to track102, the towerman moves lever 11a to the reverse operating (indication) position; As soonas contact N of Vlever 11a opens, contact 53 on relay '24 opens, but a circuit is'established which may-be traced as follows: from battery `(wire 51) thence 'via wiresA 71 and 84,' lamp 89, wire 82 to` wire 54, holding coil on relay 24, wires 55 and 56,contac`t RD of lever la (now closed), wire 57, Contact 34er; switch mechanis-m', wire' 60, motor field 32'for reverse movement, motor 14, wire 6l to battery (wire 50). Lamp 89'has a resistance such' that current flow in this circuit, Vjust traced, is not sufficient to energize relay 24 to vclose contact 53 or to start the switch mechanism inioperation. "Current new in this circuit-is indicatedto the mot'orman (train at lsignal 16) bythe lighting of lamp 89 and,

by rule or design of the signal` associated therewith, the motorman is instructed to operate release means 94 and, with the closing of vContact 98, a low resistance shunt circuit is established around lamp 89. When this shunt circuit is established, increased current, sufficient to operate stick relay 24 to close contact 53, flows in the circuit. With the closing of contact 53 the func.- tioning of the switch operating system is the same, as previously explained, until contact 34 on switch operating mechanism opens at the com,- pletion of the movement, which opensthe operating circuit thus deenergizing relay 24-and contact 53 opens. With the closing of contact 96 on the release means 94, lamp 89 is extinguished thus standing as an indication tothe motorman that the switch operating mechanism has begun to operate. After contact 53 opens, switchniotor 14 Icannot be energized as long as either track circuit section'A or B is occupied, unless. lever 11a is put in proper position and the same positive co-operation of the motorrnan obtained as before.

.After the completion of an operation thus per-` formed the towerman may complete the movement of lever 11a and clear signal 16-or the lmotorman may proceed by instruction or hand signal but'the train being stopped cannot accelerate to overrun the switch points before the switch movement is completed. f

In connection with relay 24, I have provided a circuit including battery (wire51) wire 52, 0011- tact 68 on relay 24, wire 69, relay indicator lamp 70 to battery`(wire 50). Contact 68is made vand this circuit completed with lamp .'10 lighted whenever relay `24is deenergized. c Therefore, whenever the pick up circuit of relay 24 is openand the lever lla is moved to complete an .operating circuit and resulting in the lighting of special signal lamp 89, lamp 70 will be lighted indicating to the towerman that the switch will not move. Now, when relay 24 is energized by the closing of release contact 98, the lamp 70 will beextinguished thusindicating to the towerman that release contact 98 has been operated. It should be noted that in the event ofthe pick up circuit of relay 24 being completed by the closing oi track relaycontacts 72 and 74, Contact 53 of relay 24 will close and the switch movement will be started just the same as'though release Contact 98 had beenoperated-'and obviously, under these conditions lan1ps'89 and 70 will become extinguished removing the .indication to operate push button 94 and, also; informing the towerman that the switch operating mechanism has begun to operate.

The operation of switch lll` by lever l11a is precisely the same as has beendescribed hereinbefore for the operation of switch 11 by lever 11a. It will be noted that as I have prexed the numeral 1 to characteristic reference 11 and obtained characteristic reference 111, so, also, I have prexed the numeral 1 -to the corresponding character references throughout the parts associated with the operation of switch 111 and have also doubled up on the section letters, and with this understanding it is believed that expanding the specification to describe the operation with respect to switch 111 by -lever 111er is not necessary.

Switches 11 and `lll have been illustrated and the operation described on the basis of two independent systems. Now, as a matter of fact these 'two switches may be operated simultaneously.

For example, in a well-known power operated switch operating system these two switches, illustrated as-a crossover, wouldbe controlled by two adjacent levers-strapped together in one. interlocking-machine and operated as one lever. Or, these two switches 'may -bevcontrolled by levers located in different towers.

Relay 62 isa simple relay connected, in this case, asa means to repeat the operation of contact 98 wherebyto 'control two or more circuits. As will be observed, theV controll winding of relay 62 is' included in the shunt circuit, at times mader effective, by the closing vof contact 98, to .shunt lamp S9 and cause the energizingof. relay 24. As herein' illustrated, 'relay62 provides for initiating plural control of the release circuit for switch `1'11. Thisplural control release circuit may betraced as follows: from battery (Wire 51'), contact 63 on relay 62, when closed, wire 64, contact 65 on track relay. 123, when closed, wire 66 and connecting to wire 182. A circuit including contact 163011 relay 162, when closed, may be traced similarly.

In order to distinctly describe the single releasing ofa plurality of switch operating mechanisms, I will'assume, solely forillustrative purposes only, that the two switches 11 and 111 are arranged for operation simultaneously, that is, levers 11a and 11la strapped together. Assume now that a train enters section A in the direction of the arrow, that signal 16 is in the stop position, that the remaining track sections are unoccupied-and that levers 11a and? llla and switches 1l and 111 are in the full normal position; and it is desired that said train move over switches 11 and 11-1 in the reversed position, that is, Vfrom track 101 to track 102. The towerman puts levers 11a and llla in the reverse operating (indication) position.V Switch 111 will move to the reverse position because the pick up circuit of relay 124 is completed through track relay contacts 174 on track relay 123 and 172 ontrack relay 122, so that contact 153 is closed. Switch 11 does not move becausev contact 53 on relay 24 is opencontacts R, and N of lever 11a being open and the pick up circuit through' track relay 22 contact '72 is also open. Under these circumstances special signal lamp 89 and relay -24 indicator'lamp rl0 are lighted, as "herein'beiore explained, indicating to the towerrnan'that the switch 11 has not operated, and to the motorman that the push button 94-is to be operated. The eiects of operating push button 94, under these circumstances, is as hasbeen pointed out hereinbefore. Now, assume the same set up as beforebut with track section AA occupied as well as track section A, Under these circumstances neither switch 11 nor 111 would move in response to the lever 11a llla movementfbut, as above pointed out, lamp 89 at signal 16, and relay 24 indicator lamp 70 would be lighted, and, in addition, lamp 189 at signal 116 andrelay 124 indicator lamp 179 would be lighted. Under these circumstances either push button 94 or 194 may be operated. Assume that push button 94 is operated-the shunt circuit including contact 98 and relay 62 shunts lamp 89 and relay 24 picks up closing contact 53 and switch 11 operation takes place as before explained'. Relay 62, in being energized closes contact 63 and, contact 65 on track relay 123 being closedgenelgy ows in this circuit to wire 182, thence toenergize relay 124 to close contact 153 and with the closing of oontact`153 the operation ofV switch 111 is as hereinbefore pointed out in the description of the operation of switch 11 under similar circumstances. Similar results would. be obtainedv had push button 194, closing contact 198, been operated rst, it willvbe appreciated. In the above operation several-important points should be noted: 'i 1 That either pushbutton release may be operated rst' and that the releaseqoperation oftheother of a plurality of switch operating mecha.

that relay contacts 53 and 153 open when the,

respective switch operating contacts 34 and'l'l open. 1

That sections B and BB must be unoccupied respectively for plural release operation.

That relay 62, contact 63, and associated circuit are omitted when plural released operation is not required.

That relay 62 may be omitted and the circuit including contact 63 controlled'from an additional contact operated byv push button 94.

Switch 111 may beV located as a facing point switch in track section C and arranged to divert, if need be, .trains moving in the direction of the arrow on trackl 101 justthe same as track switch 11 with or without additional track sections intervening, due regard being. had to include suitably said additional section track circuit control in the pick up circuit of relay 124. In fact any vnumber of track switches in one or more routes reached from the location of signal 16 can, by this invention, be released safely by a single push button operation, or from a plurality of such push buttons, as will be appreciated.

Contacts N and R on levers 11a and Illa may "be omitted entirely and the system will function properly by the pick up coils of relays 24 and 124 controlling through the track circuit relays only. The advantage secured by controlling these relays -with the levers in the extreme positions is that if the switches should be misplaced and the track relays open, conditions will be established automatically to move the switch into a position corresponding with the lever. The means which automatically maintain correspondence between the switch lever and switch operating mechanism are well known and form no part of this invention.

The track circuit control of the switch mechanism is always effective to control the operating current except for the interval during which the further that the appropriate contact of lever 11a "is also connected in series in said operating cir- ,signal lamp 89 which lamp 89 is shown controlled byacontact 86 on said relay 83. and, in the.v shunt circuitii including contact 98 and contact 85 around relay 83 I have included relay 62 which controls the circuit including contact 63 for the purposes set forth in the description of Fig. 1. H I desire to direct special attention to thefact thatsince this releasing and signal system is connected to the energy supply tov levers controlling the'switch operating mechanisms it is equally applicable tothe electrofpneumatic power operated switch operating system.

The labove rather specific description of one form of my` invention, is given solely by way of illustration, and is not intended, in any manner whatsoever', in a limiting sense. Obviously, my invention can assume many diiferent physical forms, and issusceptible of numerous modificaticns, andall such forms and'modications are intended tovbe included, inthis application, as come within the scope ofthe appended claims. Having describedmy inventionJnowclaim:

1. In a railway traiiic controllingsystem inf,V cluding track circuit control of poweroperated track switch operating mechanismaareleasing circuit including a manually operable contact nullifying said track circuit control, and a signal to'indicate that said contact is tobe operated, said contact controlling said signal.

2. In a railway traic vcontrolling system including track circuiti. control of power operated track switch operating mechanisms, a releasing circuit including a manually `operable contact nullifying said track circuit control, and a signal to indicate that said contact is to be operated, said releasing circuit including a relay, said relay controlling said releasing circuit.

3. In a railway traic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact nullifying said track circuit control, and a signal to indicate that said contact is to be operated, said releasing circuit including a relay, said relay controllingsaid releasing circuit, said relay also controlling the circuit of a track switch operating mechanism.

` 4. In a railway traiiic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact nullifying said track circuit control, a signal to indicate that said contact is to be operated, said releasing circuit including a relay, said relay controlling said releasing circuit, said relay controlling the circuit of a track switch operating mechanism, and a contact on said operating mechanism controlling said relay.

5. In a railway tra'iic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact nullifying said track circuit control, a signal to indicate that said contact is to be operated, said releasing circuit including a relay, said relay controlling said releasing circuit, said Vrelay controlling the circuit of a track switch operating mechanism, and a contact on said operating mechanism controlling said relay, said last mentioned contact controlling said releasing circuit.

6. In a railway traflic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact nullifying said track circuit control, a signal to indicate that said contact is to be operated, said sol releasing circuit including a relay, said relay controlling said releasing circuit, said relay controlling the circuit of a track switch operating mechanism, and a contact on said operating mechanism controlling said releasing circuit.

l7. In a railway traic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact and a lever loperated Contact in combination nulliiying said track circuit control, and` a signal to indicate that said manually operable contact is to be operated, said releasing circuit included in series in the control circuit of said operating mechanism.

'8L In a railway trafc controlling system including track circuit control of power operated track switch control circuits, a releasing circuit including a manually operable contact, a relay and a lever operated contact in series for nullifying said track circuit control, said lever Contact being regularly used in the selective control of saidswitch control circuits, said relay controlling the releasing circuit of another power operated track switch control circuit.

9. A plurality of the system set forth in clai 8, the relay in each of said releasing circuits controlling the releasing circuit of another of said plurality of systems, said last mentioned releasing circuit including a normally closed contact on a track circuit relay.

- 10. A plurality of the system set forth in claim 8, the relay in each of said releasing circuits controlling the releasing circuit of another of said plurality of systems, said last mentioned releasing circuit including a normally closed contact on a track circuit relay, the first releasing circuit operated controlling all of said releasing circuits.

11. A plurality of the system set forth in claim 8, each of said systems including a signal to indicate thatthe Vmanually operable contact associated therewith is to be operated, each of said releasing circuit relays controlling the releasing circuit of another of said plurality of systems, said last mentioned releasing circuit includingl a normally closed contact on a track circuit relay,

the first releasing circuit operated controlling all of said plurality of signals and releasing circuits. i

12. A plurality of the system set forth in claim 8, the relay in-each of said releasing circuits controlling the releasing circuit of another of said plurality of systems, the rst releasing circuit operated controlling all of said releasing circuits.

`13. In a railway traflic controlling system including track circuit control of power operated track switch operating mechanisms, a releasing circuit including a manually operable contact niulifying said track circuit control, said releasing circuit including a relay, and a signal to indicate that said contact is to be operated, said relay controlling said signal.

y GILBERT C. WHITNEY. 

